Key-bottom for pianos.



PATENTED DEC. 15, 1903.

P. DUFFY. KEY BOTTOM FOR PIANOS.

APPLIOATION FILED JAN, 9, 1903.

I no MODEL.

UNITED STATES Patented December 15, 1903.

PETER DUFFY, OF NEW] YORK, N. Y.

KEY-BOTTOM FOR PlANOS.

SPECIFICATION forming part of Letters Patent No. 746,932, dated December 15, 1903.

Application filed January 9, 1903. Serial No. 138.369- (No model.)

To all whom it may concern:

Be it known that I, PETER DUFFY, of New York, in the State of New York, have invented certain new and useful Improvements in Key-Bottoms, of which the following is a complete specification, reference being had to the accompanying drawings.

My invention relates to improvements in that part of upright and grand pianos which is technically known as the key-bottom. Formerly this member, which is designed for the support of the key-frame, was always made of wood. Latterly attempts have been made to substitute metal for wood.

The object of my invention is to produce a metal key-bottom whose construction is such as to combine the advantages of both the wood and metal structures without the disadvantages heretofore developed in each. In other Words, without entering into details, it may be stated generally that my improved keybottom combines firmness, rigidity, durability, and evenness of supporting-surface with economy of manufacture and extreme lightness in weight, every one of the features named being, as is well understood in the art, of important practical value.

In the drawings, Figure I is a top plan view of my key-bottom complete. Fig. 11 is a central longitudnal section of the subject-matter of Fig. I. Fig. III is a detail sectional view showing a simple and preferred mode of uniting the cross-pieces to the frame of my keybottom. Fig. IV is a detail sectional view showing a miter-joint of my key-bottom frame made of separate members riveted together. Fig. V is a similar View illustrating the miter-joint shown in Fig. 1, having a bent corner and cut and overlapped flanges. Fig. VI is a similar view illustrating the corner of a frame made integrally, as of pressed steel.

Referring to the numerals on the drawings, 1 and 2 indicate the side pieces, and 3 and 4 the end pieces,of the oblong rectangular frame of my key-bottom. The characteristic feature of the frame, which consists of the parts 1, 2, 5, and 4, is that it is made wholly of angle iron or steel, as is clearly shown in Figs. II and III. By the term angle iron or steel, in this connection,I refer to a single integral metal plate composed as of two plates united substantially at their edges to form an angle opening inwardly or toward the space inclosed by the frame of the keybottom. The employment of an angular frame structure, as specified, affords not only an exceedingly light and rigid structure, but also convenient means for screwing, bolting, or otherwise securing the key-bottom in position for use.

The parts 1, 2, 3, and 4 may either be made separately with miter-joints 5 and riveted togetheror they may be a part of a continuous piece having one flange cut to form the miter-joints 5 and the other bent to form the corners 6, or the said several parts may all be formed integrally and without joint, as by casting or by pressingthe frameintoshape out of steel.

Crosspieces 7, preferably made of T iron or steel, are secured by any suitable means to the parts 1 and 2, so that the surfaces of the frames 1 2 3 4 and the cross-pieces 7 shall be flush and even one with the other. In order to fit the cross-pieces 7 in place, the upper plate may be cut away and fitted and the opposite ends of the supportingflange 8 bent to form terminal plates 9, which abut against the opposite side plates of the parts 1 and 2 and are secured to them, as by rivets 10. A firmer joint may be secured between the cross'pieces and the main frame by shearing out a tongue of metal from the flange 8 directly underneath the top plate of the cross-piece and bending down the end of the top plate into the space so formed in order to accommodate and iit the top plate of the side pieces 1 and 2. This construction is shown in Fig. III, in which 11 indicates the depressed end of the top plate 12, 13 the side piece of an angle-iron frame, and let the top piece thereof. 15 indicates rivets by which the parts 11 and 14 may be immovably secured together. The use of the plates 9 and rivets 10 is contemplated in connection with the parts 11 and rivets 15, and in connection with either or both the usual means or any preferred means for deadening vibration or preventing rattling between contacting sur-.

faces may be employed.

I have deemed it unnecessary in this specification addressed to those skilled in the art of piano manufacture to illustrate either the frame into which the key-bottom is built or the key-frame which surmounts the key-b0t tom, because the construction and relative location of such parts with reference to keybottoms heretofore employed are Well understood in the art, and it is believed that the substitution of'my improved key-bottom for those heretofore employed Will offer in practice no difficulties Which can not be overcome by the manufacturer exercising ordinary mechanical skill.

In the foregoing specification I have described the frame of the key-bottom as made of angle-iron or steel and the cross-pieces thereof as made of. T iron or steel. In the claims I shall simply designate those parts as being made of angle-iron or T-iron, because those terms have a'familiar significance, and it is the structural features of such members which I rely upon to support the ap pended claims and not the material of which the members are made.

What I claim is 1. As an improvement in pianos a key-bottom comprising a frame made of end and side pieces composed respectively of angle-iron consisting of metal plates united at their edges in an angle opening inwardly, or toward the space inclosed by the frame of the key-bottom, and cross-pieces secured to the side pieces.

2. As an improvement in pianos a key-bottom comprising aframe made of end and side pieces composed respectively of angle-iron consisting of metal plates united at their edges in an angle opening inwardly, or toward the space inclosed by the frame of the key-bottom, and T-iron cross-pieces secured to the side pieces.

3. As an improvement in pianos a key-bottom comprising a frame made of end pieces and side pieces composed of angle-iron consisting of metal plates united at their edges in an angle opening inwardly, or toward the space inclosed by the frame of the key-bottom, cross-pieces of T-iron provided with terminal plates, and means for securing said terminal plates to the side pieces of the frame.

at. A key-bottom comprising a frame made of angle-iron and cross-pieces made of T-iron secured thereto, the ends of the top plates of the cross-pieces respectively being depressed to fit the top plate of the frame, and means for securing the parts together.

In testimony of all Which I have hereunto subscribed my name.

PETER DUFFY.

Witnesses:

G. WM. MONTGOMERY, L. N. NARBONN. 

